If the service is included, you can make an appointment for annual technical inspection here: https://www.sba.bg/snews/v/1329 

Validity check: https://rta.government.bg/services/check-inspection/index.html

All links (references to websites within the meaning of the Commercial Act) are provided for informational purposes only and are non-binding. Full responsibility for the accessibility, content, and consequences of using these websites lies solely with the creators and/or owners of those sites.